Sensorineural hearing loss (SNHL), which typically originates in the inner ear, is the most common otologic problems caused by aging and noise trauma. The cochlea, a delicate and complex biological mechanosensory transducer, has been extensively studied with the goal of improving diagnosis of SNHL, and developing therapeutic approaches for it. Today, clinical imaging of the cochlea is limited to compute tomography scans and magnetic resonance imaging, neither of which provide intracochlear structural detail due to limited resolution. Physical Sciences Inc., in collaboration with Massachusetts Eye and Ear Infirmary, proposes to develop an endoscopic multimodal optical imager that combines optical coherence tomography (OCT) and autofluorescence imaging (AFI) to simultaneously acquire structural and biochemical changes related to SNHL. A laboratory OCT/AFI imager will first be built and evaluated on a mouse model of cochlear hearing loss. Then a prototype endoscopic OCT/AFI imager will be developed and its feasibility for human use will be tested using cadaveric temporal bones in Phase I. The in vivo testing of the endoscopic dual modality will be performed during the Phase II program. If successful, this technology will contribute to significant improvement in the diagnosis of SNHL. Furthermore, this technology can also be used to assist in surgical planning during inner ear surgery such as cochlear implant surgery.